Dynamic simulation of motion effects in IMAT lung SBRT.
Dynamic simulation of motion effects in IMAT lung SBRT.
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DOI：
10.1186/s13014-014-0225-3
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发表时间：
2014-11-01
期刊：
影响因子：
--
通讯作者：
Teo BK
中科院分区：
文献类型：
--
作者：
Zou W;Yin L;Shen J;Corradetti MN;Kirk M;Munbodh R;Fang P;Jabbour SK;Simone CB 2nd;Yue NJ;Rengan R;Teo BK
调强弧疗(IMAT)已广泛应用于肺癌的立体定向体部放射治疗(SBRT)。虽然治疗剂量是在静态计算机断层扫描(CT)图像上优化和计算的，但靶点和直线加速器多叶准直器(MLC)运动之间的相互作用的影响没有得到很好的描述，可能会导致提供剂量和计划剂量之间的偏差。在这项研究中，我们通过使用动态CT数据集模拟动态剂量传递，研究了交互作用对靶区和危险器官(OAR)的剂量学影响。回顾分析15例I期非小细胞肺癌(NSCLC)患者接受SBRT治疗，肿瘤移位大于10 mm，分4次照射，剂量50Gy.每个IMAT计划最初都是使用两个圆弧进行优化的。通过使用包含控制点的时间戳的机器交付日志文件，将每个控制点的MLC叶位置、机架角度和交付光束监测单元(MU)与4D-CT的不同呼吸时相关联，来执行模拟的动态交付。在治疗计划系统中计算与4D-CT剂量的每个阶段相关的剂量图，并使用可变形图像配准将其累积到4D-CT的呼气阶段。在CT呼气相重新计算原始IMAT计划，并与动态模拟结果进行比较。PTV的剂量覆盖范围在静态模拟和动态模拟之间显示出可以忽略的变化。PTV V95%和V90%相差不到1.5%。PTV V95%和V90%覆盖率的平均分割间效应和累积剂量学效应均小于0.5%，桨的平均剂量效应为0.8Gy.然而，在靶点靠近器官的患者中，在大血管和支气管上观察到了高达4.9Gy和7.8Gy射线的巨大变化。每个SBRT部分以及所有四个部分的目标剂量覆盖范围和OAR限制的变化有限。在患者的关键器官上观察到较大的剂量变化，这些器官离靶区较近。
Intensity modulated arc therapy (IMAT) has been widely adopted for Stereotactic Body Radiotherapy (SBRT) for lung cancer. While treatment dose is optimized and calculated on a static Computed Tomography (CT) image, the effect of the interplay between the target and linac multi-leaf collimator (MLC) motion is not well described and may result in deviations between delivered and planned dose. In this study, we investigated the dosimetric consequences of the inter-play effect on target and organs at risk (OAR) by simulating dynamic dose delivery using dynamic CT datasets. Fifteen stage I non-small cell lung cancer (NSCLC) patients with greater than 10 mm tumor motion treated with SBRT in 4 fractions to a dose of 50 Gy were retrospectively analyzed for this study. Each IMAT plan was initially optimized using two arcs. Simulated dynamic delivery was performed by associating the MLC leaf position, gantry angle and delivered beam monitor units (MUs) for each control point with different respiratory phases of the 4D-CT using machine delivery log files containing time stamps of the control points. Dose maps associated with each phase of the 4D-CT dose were calculated in the treatment planning system and accumulated using deformable image registration onto the exhale phase of the 4D-CT. The original IMAT plans were recalculated on the exhale phase of the CT for comparison with the dynamic simulation. The dose coverage of the PTV showed negligible variation between the static and dynamic simulation. There was less than 1.5% difference in PTV V95% and V90%. The average inter-fraction and cumulative dosimetric effects among all the patients were less than 0.5% for PTV V95% and V90% coverage and 0.8 Gy for the OARs. However, in patients where target is close to the organs, large variations were observed on great vessels and bronchus for as much as 4.9 Gy and 7.8 Gy. Limited variation in target dose coverage and OAR constraints were seen for each SBRT fraction as well as over all four fractions. Large dose variations were observed on critical organs in patients where these organs were closer to the target.
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影响因子：
5.7
作者：
Verbakel, Wilko F. A. R.;Senan, Suresh;Lagerwaard, Frank J.
通讯作者：
Lagerwaard, Frank J.
影响因子：
3.5
作者：
Schaefer, M;M端nter, MW;Debus, J
通讯作者：
Debus, J
影响因子：
3.5
作者：
YU, CX
通讯作者：
YU, CX
DOI：
10.1016/j.ijrobp.2010.02.059
发表时间：
2011-01-01
影响因子：
7
作者：
Ong, ChinLoon;Verbakel, Wilko F. A. R.;Senan, Suresh
通讯作者：
Senan, Suresh
影响因子：
3.8
作者：
Court, Laurence E.;Seco, Joao;Lingos, Tania
通讯作者：
Lingos, Tania